John William Casilear was born on June 25, 1811 in New York City, New York, United States. He was the third of the nine children of John and Rebecca (Stevens) Casilear. The Stevenses were a prominent family in New Jersey. Casilear's paternal grandfather, Francis Casilear, as a young man came from Barcelona, Spain, to New York City, where he died in 1796, and was buried in St. Paul's churchyard.
His first professional training was under prominent New York engraver Peter Maverick in the 1820s.
As the only support of a widowed mother and several brothers and sisters, he worked steadily and advanced to hold an interest in the American Bank Note Company, which he did not relinquish till 1857, thus acquiring a handsome competence. Intimately associated with Asher B. Durand, Edmonds, Kensett, and Rossiter, he was in close touch with the National Academy of Design as a student and exhibitor, becoming an associate in 1835, at a time when, as he modestly said, "The Academy took in anybody. " In his case, however, the producing of graceful designs for bank notes, with more than ordinary skill in the use of the graver, and the painting of landscapes, gave probably well-founded reasons for such a distinction. He knew and received advice from Thomas Cole and, in 1840, he was afforded an opportunity to go to Europe with Durand, Kensett, and Rossiter, where he visited the galleries with them and gathered a harvest of sketches and studies. Returning to New York the following year, he did not yet allow the brush entirely to displace the burin, which had so far assured his material well-being. He produced one of the finest American engravings of the period, a reproduction of Daniel Huntington's "Sibyl, " which was published by the American Art Union. In sharpness and decision of line it has been considered worthy of the old master engravers.
During another trip to Europe in 1857, he visited Switzerland, making a number of studies and sketches of romantic landscapes, from which he afterward painted pictures. One of his earlier exhibits at the Academy, "Storm Effect" wind and rain passing over a summer landscape drew attention as a forceful presentation of this striking phase of natural phenomena. "Moonlight in the Glen" depicted the rushing waters of a stream between forest - clad banks, reflecting the light of a full moon rising in the clear sky above. But as a whole, Casilear's pictures, in subject and treatment, harmonized with the even tenor of his life. After he had completely relinquished his engraving interests about 1857, his studio in New York during the latter part of his career was at 51 West Tenth St. , where a number of distinguished painters lived and worked. Having acquired the means that assured relief from material cares by the steady industry of his earlier years, he was now able to undertake the production of a series of pictures that reflected usually the more peaceful aspects of American landscape. He was an active member of the Artists' Fund Society which held yearly exhibitions, and at each succeeding exhibit of the National Academy of Design, his landscapes were remarked for their sunny skies, silvery clouds, quiet reaches of rivers and lakes between broad meadows and distant hills. "Lake George, " "Adirondack Scenery, " "Genesee Meadows, " and a "Connecticut Riverside, " alternated with reminiscences of European trips that would occasionally appear as "Lake Leman, " "Swiss Scenery, " or "The Jungfrau" by which he was represented in the Centennial Exhibition of the National Academy of Design, held at Washington and New York in 1926. Casilear's work, like that of his companions who began their art in the precise school of engraving, was marked by careful finish, contrasting with the more self-assertive technique of the impressionists who followed. He and his associates may not have been as dexterous as their followers in the free use of the brush, and like Cole were directly or indirectly influenced by the classical landscapes of Claude Lorraine; but they were deeply in love with nature, which they approached in a reverent and poetic spirit. They produced pictures remarkable for their simple, unaffected beauty, and have a definite place in the development of American landscape art.
He was elected a full member of the National Academy of Design in 1851, having been an associate member since 1833, and exhibited his works there for over fifty years.
He was also an active member of the Artists' Fund Society.
Casilear was married in 1867 to Ellen M. Howard of Tamworth, N. H.
